At the Gatestone Institute, a group of journalists with diverse backgrounds and outlooks reviews world events with a view to American security, with special emphasis on the Middle East. Our focus this week: What does Israel do in the context of a debacle in U.S. foreign policy under the Obama administration? Our conclusion is that Israel's reasons to strike Iran have multiplied with the emergence of a Muslim Brotherhood threat on its southern border and the possibility of an Egyptian-Iranian rapprochement.

Israeli President Shimon Peres, supported by a substantial section of Israeli opinion, insists that Israel cannot strike Iran's nuclear program without the support of the United States. President Obama, as Ha'aretz defense analyst Amos Harel observes, has done everything to dissuade Israel from attacking Iran short of appearing in person before the Knesset. Senior American officials, most recently Joint Chiefs chairman Gen. Martin Dempsey, have been trotted out to assert that Israel can't stop Iran's nuclear program single-handed.

The problem is that American foreign policy faces catastrophic failure, or rather a comprehensive set of failures, bearing directly on Israeli security. Not only have sanctions failed to deter Iran from pursuing a nuclear weapons program, but the Islamic Republic has broken out of diplomatic isolation. Turkey, supposedly America's partner in regional diplomacy, has reached out to Russia and China. And Egypt has reached out to Iran while threatening Israel in the Sinai. China is hosting a summit of the Non-Aligned Movement at which Iran will assume the organization's three-year rotating chairmanship. Egyptian President Morsi will visit Tehran on Aug. 25 on his way back from the summit.

In our April 12 summary, we concluded that

...the fluid and chaotic situation in the Eastern Mediterranean and the rapidly dwindling pre-Islamist-takeover interregnum in Egypt both argued in favor of the likelihood of an Israeli strike on Iran. The current lack of real equilibrium is favorable for -- and even invites -- radical game-changing actions. Whatever equilibrium is established in the future (whenever that is) is likely to be much less favorable for Israel and more favorable for Iran, insofar as both Israel and the US will be in weaker positions and their Sunni rivals will be both weaker and poorer.

The shift towards a new equilibrium "much less favorable for Israel and more favorable for Iran" was already in progress as we wrote, with the purge of the Egyptian military's old guard and its replacement by officers allied to the Muslim Brotherhood. If Israel does nothing, it is likely to confront

1) A major Egyptian military presence in the Sinai in contravention of the Camp David treaty. An Egyptian build-up is already in progress.

2) An open alliance between Cairo and the Hamas government in Gaza, allowing Hamas to acquire new offensive capacities. As Amos Harel observed in yesterday's roundtable of Gatestone analysts, Israel already faces rocket attacks in parts of the country previously considered immune.

3) An alliance between Sunni Muslim Brotherhood elements in Syria and Iranian-sponsored Shi'ite irregulars, and Hizbollah in Lebanon.

Threats to Israel from the Sinai, Gaza, Lebanon and Syrian borders are likely to worsen as the Egyptian rapprochement with Iran proceeds. Iran's capacity to retaliate against any prospective Israeli strike will be enhanced and may include threats from Egypt.

The dilemma facing Jerusalem is that Israel can't live without the United States, but it also can't live with it. That may compel Israel to maneuver independently of Washington. As Rotem Sella reported on The Gate Aug. 17, there is speculation that Israel may concede the European natural gas market to Russia in return for Russia's forbearance in delivering anti-aircraft systems to Iran.